Improper locking in Linux kernel - CVE-2025-39779

CSH
CYBERSECURITY HELP
Sign In REGISTER
 
Main Vulnerability Database Vulnerabilities #VU115489

Improper locking in Linux kernel - CVE-2025-39779

Published: September 16, 2025


Vulnerability identifier: #VU115489
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-39779
CWE-ID: CWE-667
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to improper locking within the btrfs_subpage_set_writeback() function in fs/btrfs/subpage.c. A local user can perform a denial of service (DoS) attack.


Affected software

Linux kernel
Debian Linux
Ubuntu
linux (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-xilinx (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-ibm (Ubuntu package)
linux-nvidia-lowlatency (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-gcp-6.8 (Ubuntu package)
linux-azure-6.8 (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-realtime-6.8 (Ubuntu package)
linux (Debian package)

How to mitigate CVE-2025-39779

Install update from vendor's repository.

linux (Ubuntu package) - addressed in versions 6.8.0-100.100, 6.8.0-1047.51
linux-aws-fips (Ubuntu package) - addressed in versions 6.8.0-100.100+fips1, 6.8.0-1046.49+fips1
linux-lowlatency (Ubuntu package) - update to 6.8.0-100.100.1
linux-hwe-6.8 (Ubuntu package) - addressed in versions 6.8.0-100.100.1~22.04.1, 6.8.0-100.100~22.04.1
linux-xilinx (Ubuntu package) - addressed in versions 6.8.0-1023.24, 6.8.0.1023.24
linux-aws (Ubuntu package) - addressed in versions 6.8.0-1030.33, 6.8.0-1043.44, 6.8.0-1043.44~22.04.1, 6.8.0-1046.49~22.04.1
linux-gcp (Ubuntu package) - addressed in versions 6.8.0-1043.48, 6.8.0-1047.50~22.04.2
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1044.44, 6.8.0-1044.44~22.04.1
linux-nvidia-lowlatency (Ubuntu package) - update to 6.8.0-1046.49.1
linux-azure (Ubuntu package) - update to 6.8.0-1046.52
linux-azure-fips (Ubuntu package) - update to 6.8.0-1046.52+fips1
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1047.50+fips1
linux-gcp-6.8 (Ubuntu package) - update to 6.8.0-1047.50~22.04.2
linux-azure-6.8 (Ubuntu package) - update to 6.8.0-1051.57~22.04.1
linux-raspi-realtime (Ubuntu package) - addressed in versions 6.8.0-2037.38, 6.8.1-1041.42
linux-realtime-6.8 (Ubuntu package) - update to 6.8.1-1041.42~22.04.1
linux (Debian package) - update to 6.12.48-1

External References

Related Security Bulletins